HW first lesson

.gitignore

@@ -41,3 +41,5 @@ coverage
 config/settings.local.yml
 config/settings/*.local.yml
 config/environments/*.local.yml
+/.ruby-gemset
+/.idea/*

.ruby-version

@@ -1 +1 @@
-ruby-3.3.0
+ruby-3.3.6

Gemfile

@@ -14,6 +14,9 @@ gem 'activerecord-import'
 gem 'sprockets-rails'
 gem 'slim-rails'
 
+# Serializers
+gem 'alba'
+
 # Распаковка архивов
 gem 'rubyzip', require: 'zip'
 

Gemfile.lock

@@ -95,6 +95,8 @@ GEM
       uri (>= 0.13.1)
     addressable (2.8.7)
       public_suffix (>= 2.0.2, < 7.0)
+    alba (3.5.0)
+      ostruct (~> 0.6)
     arbre (1.7.0)
       activesupport (>= 3.0.0)
       ruby2_keywords (>= 0.0.2)
@@ -448,6 +450,7 @@ DEPENDENCIES
   activeadmin
   activeadmin_addons
   activerecord-import
+  alba
   bundler-audit
   capybara
   config

app/controllers/application_controller.rb

@@ -1,4 +1,5 @@
 class ApplicationController < ActionController::Base
+  include Pagination
   # Only allow modern browsers supporting webp images, web push, badges, import maps, CSS nesting, and CSS :has.
   allow_browser versions: :modern
 end

app/controllers/books_controller.rb

@@ -0,0 +1,6 @@
+class BooksController < ApplicationController
+  def index
+    books = paginate(Book.all)
+    render json: BookSerializer.new(books)
+  end
+end

app/controllers/concerns/pagination.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+# Методы фильтрации сортировки и паджинации
+module Pagination
+  extend ActiveSupport::Concern
+  # DEFAULT_LIMIT = Settings.app.items_per_page || 100
+
+  def paginate(items)
+    curr_page = params[:page] || 1
+    limit = params[:per_page] || Settings.app.items_per_page || 100
+    items.page(curr_page).per(limit)
+  end
+end

app/serializers/book_serializer.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+class BookSerializer
+  include Alba::Resource
+  root_key!
+
+  attributes :id, :title
+end

config/database.yml

@@ -5,10 +5,10 @@ default: &default
   prepared_statements: false
 
 postgre: &postgre
-  host: <%= ENV.fetch('POSTGRES_HOST', 'localhost') %>
+  host: <%= ENV.fetch('POSTGRES_HOST', '127.0.0.1') %>
   port: <%= ENV.fetch('POSTGRES_PORT', '5432') %>
-  username: <%= ENV.fetch('POSTGRES_USER') { 'igorsimdyanov' } %>
-  password: <%= ENV.fetch('POSTGRES_PASSWORD') { '' } %>
+  username: <%= ENV.fetch('POSTGRES_USER') { 'admin' } %>
+  password: <%= ENV.fetch('POSTGRES_PASSWORD') { 'admin' } %>
 
 development:
   <<: *default
@@ -17,6 +17,7 @@ development:
 
 test:
   <<: *default
+  <<: *postgre
   database: library_test
 
 production:

config/routes.rb

@@ -24,6 +24,9 @@
   # Can be used by load balancers and uptime monitors to verify that the app is live.
   get 'up' => 'rails/health#show', as: :rails_health_check
 
+  get "books/(:page)" => 'books#index', page: /\d+/
+  # resources :books, only: :index - Я бы предпочел маршруты строить ближе к REST, а номер страницы передавать в query параметрах, например /books?page=2&per_page=100
+
   # Render dynamic PWA files from app/views/pwa/*
   get 'service-worker' => 'rails/pwa#service_worker', as: :pwa_service_worker
   get 'manifest' => 'rails/pwa#manifest', as: :pwa_manifest

docs/layers.pulm

@@ -0,0 +1,7 @@
+@startuml
+Router -down->[use] Controller
+Controller -down->[use] Command
+Controller -down->[use] Model
+Command -down->[use] Model
+Controller -down->[use] Serializer
+@enduml

spec/rails_helper.rb

@@ -64,4 +64,5 @@
   # config.include Devise::Test::ControllerHelpers, type: :request
   config.include LoaderHelpers
   config.include LoginHelpers, type: :feature
+  config.include RequestHelper, type: :request
 end

spec/requests/books_spec.rb

@@ -0,0 +1,24 @@
+require 'rails_helper'
+
+RSpec.describe BooksController, type: :request do
+  let(:language) { create(:language) }
+  let(:folder) { create(:folder) }
+  let(:per_page) { 25 }
+  let!(:books) { create_list(:book, 30, language: language, folder: folder) }
+
+  before do
+    allow(Settings.app).to receive(:items_per_page).and_return(per_page)
+  end
+
+  describe "GET /index" do
+    it "returns http success" do
+      get "/books/2"
+      expect(json[:books].size).to eq(5)
+    end
+
+    it "returns http success" do
+      get "/books"
+      expect(json[:books].size).to eq(25)
+    end
+  end
+end

spec/support/request_helper.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+module RequestHelper
+  def json
+    JSON.parse response.body, symbolize_names: true
+  end
+end